Invalid HTML in Echo notification list pop-up.
http://dev.w3.org/html5/markup/a.html#a-constraints says:
"The interactive element a must not appear as a descendant of the a element."
The current code is:
(trimmed)
```lang=html
<ul class="mw-echo-notifications">
<li class="mw-echo-notification">
<a class="mw-echo-notification-wrapper"> <!-- wrapping [a] -->
<div class="mw-echo-state">
<img class="mw-echo-icon">
<div class="mw-echo-content">
<div class="mw-echo-title">
<a class="mw-echo-grey-link">...</a> ... <!-- nested [a] -->
</div>
<div class="mw-echo-notification-footer">
před 2 hodinami |
<a class="mw-echo-notification-secondary-link mw-echo-grey-link" >...</a> <!-- nested [a] -->
</div>
<a class="mw-echo-notification-primary-link">...</a> <!-- nested [a] -->
</div>
</div>
</a>
</li>
</ul>
--------------------------
**Version**: unspecified
**Severity**: normal```